This invention relates to a battery charging device, and is particularly useful for charging batteries of portable telephones. However, the device of the invention may also have application in charging batteries used in a wide variety of other applications, such as in video cameras, portable cameras and the like.
Portable telephones and other portable devices which require electrical energy to operate frequently use rechargeable batteries. Such batteries are releasably attachable to the portable telephone, provide the necessary energy, and discharge over a period of time and during use. The battery may then be removed ad placed in a battery charging device which is supplied with energy from a conventional electric outlet in a home, office or car. After a given period of time, depending on the nature and specifications of the battery, the battery can be recharged and is then available for further use.
It will be appreciated that there are a large number of rechargeable batteries on the market, each battery having a particular size, structure, power requirement and other features. For this reason, each type of battery typically requires its own specialized and custom designed battery charger.
U.S. Pat. No. 4,974,250 (Tomiyori) teaches an adaptor for mounting a portable telephone on a vehicle. The adaptor allows either one of a simple handset and a multi-function handset to be used as desired. When a multi-function handset is used with the adaptor, the adaptor is switched on and off by a power switch provided on the handset. When a simple handset is used, the adaptor is switched on and off by an ignition switch which is provided on the vehicle.
U.S. Pat. No. 4,963,812 (Mischenko) discloses a battery charger housing for batteries of differing dimensions. Batteries for charging are inserted into a recess in the battery charger housing and are captivated by a lip portion which extends into the recess. The lip portion has a plurality of surfaces, one of which surfaces contacts a surface of a battery of one size and maintains the position of the battery against the charging contacts of the battery charger. Different size batteries contact different lip surfaces. Mischenko provides only a single bottom surface for receiving the battery, and the possible use for a wide-ranging variation of battery sizes is very limited.
U.S. Pat. No. 4,850,006 (Sasaki) discloses a booster and charger unit used for hand-held portable telephones. It is capable of preventing a casing of the unit from being heated to an excessive temperature. The casing has therein a charging device for charging a battery, and a temperature sensor responsive to the temperature of the casing. The unit does not appear capable of charging batteries of different sizes
U.S. Design Pat. No. 307,016 (Watanabe) illustrates a charger for a portable radio telephone. The design patent illustrates the particular design of a charger, and appears capable of receiving only a specific size battery.